Well, I am really happy to help you with that.
Generally, we will say in Egypt :
عندك كام سنة؟ for boys
عندِك كام سنة؟ for girls
If you write them they look the same but the difference in the pronunciation.
Andak = which means "You have" عندك
Kam= How many
Sana = Year
for girls, you usually have to use "Kassrah" so it will become
Andik instead of "Andak"?عندِك
You can start your question with "Andak for boys, and Andik for girls, to ask if they have something.
You can ask me for more clarification and I'd be super happy to assist.
يومك سعيد = Yumak Sa'eed= Have a happy day.